Ammonia-oleate is used in this paper as surface modification agent to coat oil-based monodisperse magnetic iron oxide nanoparticles (MMIONPs) in water-soluble bilayer-stabilized MMIONPs by microemulsion method. The oleate-coated MMIONPs are made of thermal decomposition of submicrometer hematite powder in oleic acid and 1-octadence mixture via controlled dissolution-recrystallization process. Transmission electron microcopy (TEM), Thermogravimetric analyzer (TGA) and Fourier transformation-infrared (FTIR) spectroscopy are used in the process to characterize product samples before and after modification processes. The colloidal stability of bilayer-stabilized MMIONPs in various pH values of solvents and salt concentration was elaborated characterized by the dynamic light scattering (DLS) technique. The DLVO theory is also used for qualitative characterization on the colloidal stability of bilayer-coated MMIONPs in various conditions. The experimental data indicates that the bilayer-coated MMIONPs thus obtained with low concentration to aggregate was initially at the pH value less than 7, and salt concentration over 0.2 M. Also, the testing results are found satisfactory.
|Number of pages||9|
|Journal||Journal of the Chinese Society of Mechanical Engineers, Transactions of the Chinese Institute of Engineers, Series C/Chung-Kuo Chi Hsueh Kung Ch'eng Hsuebo Pao|
|Publication status||Published - 2008 Dec 1|
All Science Journal Classification (ASJC) codes
- Mechanical Engineering